There are examples from industry where presumption of the self-interest model yields inferior results. In the early 1980s, after a long history of low productivity, low quality products, and low employee job satisfaction, a GM plant in California shut down its operation. Shortly thereafter, it entered a venture with Toyota called the New United Motor Manufacturing, Inc. (NUMMI). Under this new merger, GM provided the plant and Toyota took over the management. The central difference between the old GM plant and the NUMMI plant was their management structure. Toyota's success in the automotive industry has been attributed to its innovation in management and to its shift away from the GM assembly line model and presumption of self-interest to an emphasis on other values such as teamwork. Advances in the evolutionary theory also challenge the selfish actor model. A central puzzle for evolution has been to explain how "altruism," understood in the biological context to impose a fitness cost on its actor and confer a benefit to its recipient, could have evolved in nature. Given that natural selection selects against fitness-decreasing traits, it seems that altruism—the disposition to sacrifice oneself for the good of the others—ought to have been eliminated. Darwin suggested that traits that work to the detriment of the individual could evolve if they were traits that benefitted the group to which that individual belonged. According to this hypothesis (known as "group selection"), some behaviors or traits evolved because members of groups containing those traits did better than members of groups that did not. While altruistic behaviors may be individually disadvantageous compared to selfish behaviors at the individual level, groups of altruistic individuals will be at a selective advantage over groups of selfish individuals.